When scientists talk about the cryosphere, they mean the places on Earth where water is in its solid form, frozen into ice or snow. Read more ...

Cryosphere Glossary

equinox

either of the two points of intersection of the sun's apparent annual path and the plane of the earth's equator; in the northern hemisphere the spring (vernal) equinox falls on or about 21 March, and the autumnal equinox on or about 22 September.